Classification (and/or Division) papers encourage the writer to invent or discover categories of classification and then apply them to a specific subject. The writer then analyzes the results of the process to discover something new from the information gained by the categorization. This type of paper will arrange things in categories or divide a subject into its parts and then hypothesize about characteristics shared by those parts.
The goal is not dissection, but to say something meaningful about how the whole of a subject relates to its parts or how the parts of a subject relate to its whole. Remember, you are trying to communicate something new and interesting discovered by applying the categories to your subject, so it is important to make the categories meaningful.
In order to perfect the modes, or ways in which you go about classifying or dividing, it is important to include some brainstorming work before writing the paper. Generate as many characteristics for a category or subject as you can before you begin writing. While writers often focus on listing the characteristics that represent a subject, telling what it is or what it is made up of, a writer might also make distinctions based on the absence of a characteristic. The writer will then tell what the subject is not or what it is not made up of or what it lacks.
Keep the overall point or purpose of the paper in mind during the writing and revision process to keep the categories on track. Pay close attention to the way in which those categories are organized. The order in which they appear can easily imply a certain relationship among them.
Example: Classification of Birds
Birds of Prey are often classified by what they eat, how they hunt, and specific anatomical aspects (body parts) that they have evolved to aid them in hunting. Birds of Prey could be characterized by their lack of melodic bird-call, like that of a lark. Birds of Prey could be classified by their earth-tone coloring, or lack of colorful plumage.
It is really all about the way in which you plan to classify them!